Carboxymethylated derivatives of diand tri-saccharide compounds and detergent compositions containing them

ABSTRACT

CARBOXYMETHYLATED DERIAVATIVES OF DISACCHARIDE COMPOUNDS SUCH AS SUCROSE AND LACTOSE AND TRISACCHARIDE COMPOUNDS SUCH AS RAFFINOSE ARE PROVIDED. THESE COMPOUNDS ARE USEFUL AS SEQUESTERING AGENTS, E.G., WATER SOFTENERS, AND ALSO AS DETERGENCY BUILDERS IN DETERGENT COMPOSITIONS. BUILT DETERGENT COMPOSITIONS ARE ALSO PROVIDED.

United States Patent @flice US. Cl. 260209 R 4 Claims ABSTRACT OF THEDISCLOSURE Carboxymethylated derivatives of disaccharide compounds suchas sucrose and lactose and trisaccharide compounds such as raffinose areprovided. These compounds are useful as sequestering agents, e.g., watersofteners, and also as detergency builders in detergent compositions.Built detergent compositions are also provided.

This invention relates to carboxymethylated diand trisaccharides whichare useful as sequestering agents and also as'detergency builders fororganic water-soluble synthetic detergents.

The compounds of the present invention have a formula selected from thegroup consisting of H H H H M; $45 6 '0 '0 1 i 1 i FormulaB Y HJHI -03,634,392 Patented Jan. 11, 1972 in which each Y represents H or CHCOOH, at least one Y being CH COOH.

Compounds depicted by Formula A are derivatives of sucrose, C H Omolecular weight, 342.2. Sucrose is a disaccharide having monocliniccrystalline form. It hydrolyzes to fructose and glucose. It is widelyfound free in juice of all land plants, in particular sugarcane, sugarbeet, and sugar maple.

Compounds depicted by Formula B are derivatives of lactose, C H O H O,molecular weight, 360.2. Lactose is a disaccharide found free in milk ofall mammals and also in pollen from Forsythia. It hydrolyzes to glucoseand galactose.

Compounds depicted by Formula C are derivatives of rallinose, C H O -5HO, molecular weight, 594.4. Raffinose is a trisaccharide derived fromsugar beets, cottonseed, eucalyptus, and other plants. It hydrolyzes tofructose, glucose, and galactose. It has colorless monoclinic needles,d. -l.465, MP. 119.

Further description of the parent materials is found in volume 13,Encyclopedia of Chemical Technology, Kirk and Othrner, copyright 1954 bythe Interscience Encyclopedia, Inc.

In the preceding formulae, as noted, each Y represents hydrogen or acarboxymethyl group. Such carboxymethylated compounds have beendiscovered to possess useful sequestering properties and detergencybuilder properties. Both of these properties are improved with anincrease in the number of carboxymethyl groups present in each compound.The maximum degree of substitution, D.S. (number of carboxymethylgroups) for sucrose and lactose is 8 and for rafiinose is 11. Inpracticing this invention in a sequestering application, it is preferredto use compounds having a degree of substitution greater than 3. Foroptimum detergency builder properties, a degree of substitution ofgreater than in each instance is preferred, e.g., greater than 4 in thecase of sucrose and lactose and greater than about 6 in the case ofraflinose.

The carboxymethylated derivatives of sucrose, lactose, and raffinoseprovided by the present invention can be prepared by manycarboxymethylating procedures. A typical preparative method, and onewhich is exemplified hereinafter, comprises a reaction between sucrose,lactose, or raffinose with an alkaline material such as sodium hydroxideto form an alkoxide of the polyhydric alcohol. The reaction product ofthis reaction is then reacted with a compound such as sodiumchloroacetate and the mixture is allowed to digest. An ordinary workupfollows these reactions in order to recover the desiredcarboxymethylated sucrose, carboxymethylated lactose, orcarboxymethylated raffinose, depending on Whatever the starting materialwas.

The following examples are given by way of specific illustration forpreparing the compounds of this invention:

EXAMPLE I Preparation of carboxymethylated sucrose A solution of 4.3 g.(0.10 equivalent) of sucrose in 19.6 ml. of water was mixed with 7.2 g.(0.18 mole) of ground sodium hydroxide and this mixture was blended forten minutes. To this was added 21.4 g. (0.18 mole) of sodiumchloroacetate and blending was again carried out for ten minutes. Themixture was then allowed to stand and digest with occasional blending,for three days until all of the sodium chloroacetate had reacted. Thisprocedure of adding sodium hydroxide and sodium chloroacetate inequivalent amounts, followed by a digestion step, was reported six timesto arrive at a completed reaction. Water was added, as needed, tomaintain a pasty consistency.

After completion of the reaction, the reaction mixture was dissolved inwater and the product was then precipitated by the addition of excess ofmethanol. The precipitate was collected by filtration, redissolved inwater, and then the precipitation-isolation procedure was repeated.There was obtained 5.4 g. of product. Final purification was effected bygel filtration using Sephadex G-lO resin.

The product was analyzed by dissolving a weighed amount of it in water,passing this solution over a column of a strongly acidic ion exchangeresin, and then titrating the resulting eluant with standardized sodiumhydroxide solution. Analysis indicated an equivalent weight of 120 forthe carboxymethylated sucrose product which corresponds to a degree ofsubstitution of 8.

EXAMPLE II Preparation of carboxymethylated lactose A solution of 4.3 g.(0.10 equivalent) of lactose in 19.6 ml. of water was mixed with 7.2 g.(0.18 mole) of ground sodium hydroxide and this mixture was blended forten minutes. To this was added 21.4 g. (0.18 mole) of sodiumchloroacetate and blending was again carried out for ten minutes. Therest of the procedure of Example I was followed and the productrecovered was carboxymethylated lactose having a degree of substitutionof 8. Carboxymethylated lactose with degrees of substitution of 6, 5, 4,2, or 1 are prepared by decreasing the amount of sodium hydroxide andsodium chloroacetate added to the reaction and also by using shorterdigestion times.

EXAMPLE III Preparation of carboxymethylated rafiinose Following theprocedure described in Example I, 5.4 g. of raffinose pentahydrate (0.1equivalent of raffinose) and 31.9 ml. of water were reacted. Sodiumchloroacetate was added as noted in Example I followed by digestion forabout three days.

The same work-up procedure was practiced to recover the desiredcarboxymethylated raffinose. The recovered product was analyzed for anequivalent weight of 130 which corresponds to a degree of substitutionof about 10.8 out of a maximum of 11. Routine adjustments in bothreaction time and digestion time result in the preparation ofcarboxymethylated rafiinose having lesser degrees of substitution.

The compounds of this invention possess a useful sequestering propertywhich makes them valuable for treating aqueous solutions containingpolyvalent metal ions (iron, calcium, magnesium, and the like) by addingto a solution an effective amount of one of the compounds describedherein, or a mixture of such compounds. Ordinarily the amount employedranges from .25 part per million to 10,000 parts per million of theaqueous solution. This embodiment of the present invention is based onthe discovery of the sequestering properties of the carboxymethylatedcompounds described herein. The optimum amount for any given watertreatment application can be readily determined by merely adding asufiicient amount of sequestrant to accomplish the desired objective.The useful sequestering properties of the compounds of the presentinvention are demonstrated by a swatch-dip procedure which measures therelative sequestering ability of a compound. The procedure involves theuse of a fabric swatch impregnated with soap and an aqueous solutioncontaining a predetermined level of calcium hardness minerals. Briefly,the procedure first calls for preparing an aqueous solution containingthe hardness minerals, at a pH of 10, and then dipping into it orimmersing in it a fabric swatch which has been impregnated with ameasured amount of soap. The swatch is allowed to remain in the solutionfor a predetermined amount of time. During this immersed period, freecalcium in the solution is being absorbed by the fabric swatch. Theamount of free calcium absorbed is then measured. The identicalprocedure is then repeated but with a predetermined concentration of asequestrant compound added to the aqueous solution containing thecalcium ions. The amount of calcium absorbed in this second instance isalso measured. Comparisons are then made between the two results, i.e.,those obtained without the use of a sequestrant against those resultsobtained with the use of a sequestrant. Differences between the amountsof calcium absorbed in demonstrations with and without sequestrants isattributed to the capability of the sequestrant to sequester or complexthe calcium ions and, thereby, reduce the amount of free calcium ionavailable for absorption upon the immersed fabric swatch. A percentageis calculated which is called percent hardness retained by sequestrant.

Several demonstrations were conducted in this manner and comparisonswere drawn between the performance of compounds of the present inventionand sodium tripolyphosphate (STP), sodium citrate, and sodiumpyrophosphate. These latter compounds are three known sequesteringagents. The data obtained from these demonstrations are tabulated belowin Table I and indicate the useful sequestering properties ofrepresentative compounds of the present invention, i.e.,carboxymethylated sucrose of Example I, carboxymethylated lactose ofExample II, and carboxymethylated ratfinose of Example III.

TABLE I Degree Percent hardness retained 1 of subsequestrant (sodiumsalts) stitution O2 03 04 O6 1. Carboxymethylated sucrose 8 43 44 53 572. Carboxymethylated lactose 8 58 63 3. Carboxymethylated railinose 10.7 43 49 5G 74 4. Sodium citrate 51. 4 58. 6 5. Sodium pyrophosphate 81.481 4 82.9 6. Sodium tripolyphosphatc 81. 4 4 91.4

1 Concentration of sequestrant in solution, percent.

In addition to the useful sequestering properties which thecarboxymethylated derivatives of sucrose, lactose, and raffinose of thisinvention possess, they are also useful as detergency builders. Inpracticing this builder embodiment, the carboxymethylated buildercomopunds described and illustrated above are used in conjunction withorganic synthetic detergents to provide built laundering and detergentcompositions.

The organic water-soluble synthetic detergents useful in the presentinvention include the anionic, nonionic, zwitterionic, and ampholyticdetergents which are illustrated and exemplified in detail in U.S. Pat.3,159,581, issued on Dec. 1, 1964, to Francis L. Diehl and assigned tothe Procter & Gamble Company. The patent and especially the disclosurebeginning at column 3, line 74, and extending to column 5, line 59 arehereby incorporated herein by reference. There are numerous otherdetergents which fall within the named classes of detergents and theycan also be usefully employed herein. Olefin sulfonate detergents suchas those described in U.S. Pat. 3,332,880 (also incorporated herein byreference) are especially useful in combination with the buildercompounds of this invention.

In practicing the present invention, a detergent and launderingcomposition comprises an organic water-soluble synthetic detergent and acarboxymethylated sucrose, lactose, or raffinose builder in a proportionby weight, respectively, of 5:1 to 1:10 and preferably 2:1 to 1:5. Thebuilt composition can be formulated as a liquid or solid form. Builtliquid compositions having an aqueous or alcoholic (ethanol) base areespecially useful. Solid formulations such as tablets, granules,powders, flakes, and the like find widespread application.

In a detergent formulation of this invention, minor amounts of othermaterials can be present which make the product more effective or moreaesthetically attractive. The following are mentioned by way of example.A soluble sodium carboxymethyleellulose or starch can be added in minoramounts (.2-2%) to inhibit soil redeposition. A tarnish inhibitor suchas benzotriazole or ethylenethiourea may also be added in amounts up toabout 2%. Fluorescers, perfume, and color while not essential in thecompositions of the invention, can alsc be added in amounts up to about3%. An alkaline material such as sodium hydroxide or potassium hydroxidecan be added in minor amounts as supplementary pH adjusters. Othersuitable additives include water, brightening agents, enzymes, sodiumsulfate, and sodium carbonate, buffers, fillers and the like.

In addition, corrosion inhibitors can also be present. Soluble silicatesare highly effective inhibitors and can be added to certain formulas ofthis invention at levels of from about 3% to about 8%. Alkali metal,preferably potassium or sodium silicates having a weight ratio of SiO :MO of from 1.021 to 28:1 can be used. M in this ratio refers to sodiumand potassium. A sodium silicate having a ratio of SiO IN2t O of about1.6:1 to- 2.45:1 is especially preferred for economy and effectiveness.

In the embodiment of this invention which provides for a built liquiddetergent, a hydrotrope can at times be found desirable. Suitablehydrotropes are water-soluble alkali metal salts of toluenesulfonate,benzenesulfonate, and xylenesulfonate. The preferred hydrotropes arepotassium or sodium toluenesulfonates. The hydrotrope salt may be added,if desired, at levels from to about 12%. While a hydrotrope is notordinarily found necessary, it can be added if so desired for any reasonsuch as to produce a product which retains its homogeneity at a lowtemperature.

The built detergent and laundering compositions of this inventionprovide best cleaning results when used in aqueous solutions having a pHof 9 to 12, preferably 9.5 to 11.5. This point can be taken into accountin formulating the complete built composition by including alkalineingredients to satisfy the pH requirement. Alternatively, alkalinematerials can be added directly to the washing solution to bring the pHinto the 912 range.

The compositions of this invention provide best cleaning results whenused at a sufficient level to provide in solution a concentration ofbuilder in the range of .02% to .5 by weight, and preferably .03% to.3%.

The following built detergent compositions illustrate this embodiment ofthe present invention:

EXAMPLE IV A granular built detergent composition having the followingcomposition provides effective laundering results in aqueous solutionshaving a pH of about 9:

Percent Sodium dodecylbenzene sulfonate, dodecyl being a linearstraight-chain radical Sodium carboxymethylated sucrose builder (D.S.=8)

of Example I 50 Sodium sulfate 14 Sodium silicate 6 Water 10 In thisexample, the sucrose builder can be replaced by a sodiumcarboxymethylated lactose of Example If (D.S.=8) or sodiumcarboxymethylated raffinose (D.S.=11) without any loss in cleaningproperties.

EXAMPLE V An effective granular built detergent composition comprises:

Percent Sodium olefin sulfonate (having 12-16 carbon atoms) 17.5 Sodiumtripolyphosphate 20.0 Sodium pyrophosphate 20.0 Sodium carboxymethylatedsucrose (D.S.=7) 10.0 Sodium sulfate 16.0 Sodium silicate 10.0

Water 4.0

In this example, the sodium pyrophosphate can be replaced on an equalweight basis by sodium carboxymethylated lactose (D.S.=5), sodiumcarboxymethylated lactose (D.S.=3), sodium carboxymethylated sucrose(D.S.=6), sodium carboxymethylated raffinose (D.S.=8), or sodiumcarboxymethylated raifinose (D.S.=4).

In addition, the sodium olefin sulfonate detergent can be replaced bysodium tallow alkyl sulfate or sodium co conut alkyl sulfate.

EXAMPLE VI An excellent built liquid detergent composition according tothis invention comprises:

Percent Sodium dodecylbenzene sulfonate (the dodecyl radical beingpolypropylene predominantly tetrapropylene averaging 12 carbonsDimethyldodecylamine oxide 6 Sodium carboxymethylated lactose (D.S.=6)20 Potassium toluenesulfonate 8 Sodium silicate (ratio SiO :No -O of2.45:1) 3.8 Carboxymethyl hydroxyet hyl cellulose 0.8

Water: Balance In practicing the built detergent composition embodimentof the present invention, the carboxymethylated sucrose, lactose, andraffinose builders described herein can be used separately or incombination either with each other, or in combination with any inorganicalkaline detergency builders or organic alkaline sequestering builderssuch as sodium nitrilotriacetate, sodium ethylenediaminetetraacetate,sodium ethane-l-hydroxy-1,1-diphosphonic acid, sodium polyitaconate, orsodium polymaleate.

As detergency builders, the carboxymethylated sucrose, lactose, andraffinose are in a class with such builders as citrate and pyrophosphatesalts. This can be demonstrated by the following evaluation:

White dress shirts, cotton T-shirts and other fabrics are distributedamong various individuals. Each dress shirt and T-shirt is worn for onenormal working day under uniform conditions and the other articles areused for their generally intended purposes. The soiled items are thenwashed in an automatic agitating type washer, for a period of tenminutes, with detergent solutions at F. temperature, :a pH of 10, and ahardness of 7 grains per gallon. After washing, the clothes are rinsedand then dried. (No fluorescers or bleaches were used).

Direct comparisons are made by a panel of five graders between pairs ofshirts and fabrics worn and soiled by the same individual. The dressshirts, T-shirts and other fabrics used are graded on the degree ofwhiteness and the degree of cleaning obtained, paying particularattention on this latter feature to the dress shirt collars and cuffs.The term cleaning or cleanliness denotes the ability of a washingcomposition to remove actual soil lines or deposits such as the creaselines of collars and cuffs where the soil is deeply embedded. Whiteness,on the other hand, denotes a more general concept which measures theability of a cleaning composition to whiten areas which are onlyslightly or moderately soiled. Clean washcloth size swatches of cottonterry cloth and muslin are washed along with the soiled clothes toarrive at an independent evaluation of the whiteness maintenance orwhiteness compositions. The relative cleaning effectiveness of eachdetergent composition in each area is graded on a raw score underU.V.-free artific al light, averaged, and then translated onto a 010scale wherein the highest grade of 10 is assigned to the relatively bestperformance obtained.

A sample detergent composition employed during the tests contains 20%sodium tallow alkyl sulfate as the detergent active (the alkyl chainlength distribution of tallow alkyl sulfate was approximately 66% C 30%C and 4% others), 50% of a builder such as sodium citrate, sodiumpyrophosphate, or the carboxymethylated sucrose, latose, or raffinosebuilders described herein, 6% sodium silicate and 24% sodium sulfate.The pH of the washing 2. A compound having a formula: solution is 10.

in which each Y represents H or CH COOH, at least By practicing thisdemonstration, it is seen that the builders of this invention aresubstantially equal in builder properties and effectiveness in areas ofcleaning and Whiteness to sodium citrate and alkali metal salts ofpyrophosphoric acid, e.g., sodium pyrophosphate.

The foregoing description of the invention has been presented describingcertain operable and preferred embodiments. It is not intended that theinvention should be so 10 limited since variations and modificationsthereof Will be obvious to those skilled in the art, all of which arewithin the spirt and scope of this invention.

What is claimed is:

1. A compound having a formula:

one Y being CH COOH.

3. A compound having a formula:

in which each Y represents H or CH COOH, at least one Y being -CH COOH.

4. A compound having a formula:

a 999 m m mm a at m w o s n u 0 c2 m I m E T d A 2 r r t n 0 a .l H fi mo m WT mh X B. Aa fl E n mTh SGF W e e a m R 577 .m 6 E566 H nwww P YcNoun s, M 1 U1 H mm 1 9 O .1 201 G mm s Y mwm 1 W 7 2 3 W mm 233 m 5 0 56 Y 0 n n C H H o O Y 0 I r e o Y C /n f CH r# I W MH V IIJVOY HHH C Y OH C O Y H C Y I. R. BROWN, Assistant Examiner US. Cl. X.R.

in which each Y represents H or CH COOH, at least one Y being CH COOH.

